#include <stdio.h>

int main()
{
    int killer = 'a';
    for (killer = 'a'; killer <= 'd'; killer++)
    {
        if (
            (killer != 'a') +
            (killer == 'c') +
            (killer == 'd') +
            (killer != 'd') == 3)
        {
            printf("killer = %c\n", killer);
        }
    }
    return 0;
}

